http://blog.csdn.net/hz932/archive/2008/03/20/2198601.aspx.Net下采用GET/POST/SOAP方式动态调用WebService的简易灵活方法(C#)一直以来，我都为动态调用WebService方法而烦恼。在.Net环境下，最常用的方法就是采用代理类来调用WebService，可以通过改 变代理类的Url属性来实现动态调用，但当xmlns改变时就会出错，似乎要重新绑定Webservice并重新编译后才能再次运行。我还试过网上的一种 动态编译并动态调用WebService的方式，这种方法效率低，而且需要有较高的权限，否则编译失败。我曾在Sql Server 2005的CLR存储过程中用此方法调用WebService时，浪费了大半天时间，无论怎么试它就是不能成功编译。于是我便不断思考其他的方法，今天晚 上终于写了一个类用于动态调用WebService，只需传入WebService地址、需调用的方法及其参数，就可以随时动态调用了。现分享给大家，代 码如下：
using System;
using System.Web; using System.Xml; using System.Collections; using System.Net; using System.Text; using System.IO; using System.Xml.Serialization; //By huangz 2008-3-19 /**//// <summary> /// 利用WebRequest/WebResponse进行WebService调用的类,By 同济黄正 http://hz932. 2008-3-19 /// </summary> public class WebSvcCaller { //<webServices> // <protocols> // <add name="HttpGet"/> // <add name="HttpPost"/> // </protocols> //</webServices> private static Hashtable _xmlNamespaces = new Hashtable();//缓存xmlNamespace，避免重复调用GetNamespace /**//// <summary> /// 需要WebService支持Post调用 /// </summary> public static XmlDocument QueryPostWebService(String URL , String MethodName , Hashtable Pars) { HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(URL + "/" + MethodName); request.Method = "POST"; request.ContentType = "application/x-www-form-urlencoded"; SetWebRequest(request); byte[] data = EncodePars(Pars); WriteRequestData(request , data); return ReadXmlResponse(request.GetResponse()); } /**//// <summary> /// 需要WebService支持Get调用 /// </summary> public static XmlDocument QueryGetWebService(String URL , String MethodName , Hashtable Pars) { HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(URL + "/" + MethodName + "?" + ParsToString(Pars)); request.Method = "GET"; request.ContentType = "application/x-www-form-urlencoded"; SetWebRequest(request); return ReadXmlResponse(request.GetResponse()); } /**//// <summary> /// 通用WebService调用(Soap),参数Pars为String类型的参数名、参数值 /// </summary> public static XmlDocument QuerySoapWebService(String URL , String MethodName , Hashtable Pars) { if (_xmlNamespaces.ContainsKey(URL)) { return QuerySoapWebService(URL , MethodName , Pars , _xmlNamespaces[URL].ToString()); } else { return QuerySoapWebService(URL , MethodName , Pars ,GetNamespace(URL)); } } private static XmlDocument QuerySoapWebService(String URL , String MethodName , Hashtable Pars , string XmlNs) { //By 同济黄正 http://hz932. 2008-3-19 _xmlNamespaces[URL] = XmlNs;//加入缓存，提高效率 HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(URL); request.Method = "POST"; request.ContentType = "text/xml; charset=utf-8"; request.Headers.Add("SOAPAction" , "/"" + XmlNs + (XmlNs.EndsWith("/") ? "" : "/") + MethodName + "/""); SetWebRequest(request);
byte[] data = EncodeParsToSoap(Pars , XmlNs , MethodName); WriteRequestData(request , data); XmlDocument doc = new XmlDocument() , doc2 = new XmlDocument(); doc = ReadXmlResponse(request.GetResponse()); XmlNamespaceManager mgr = new XmlNamespaceManager(doc.NameTable); mgr.AddNamespace("soap" , "http://schemas./soap/envelope/"); String RetXml = doc.SelectSingleNode("//soap:Body/*/*" , mgr).InnerXml; doc2.LoadXml("<root>" + RetXml + "</root>"); AddDelaration(doc2); return doc2; } private static string GetNamespace(String URL) { HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL + "?WSDL"); SetWebRequest(request); WebResponse response = request.GetResponse(); StreamReader sr = new StreamReader(response.GetResponseStream() , Encoding.UTF8); XmlDocument doc = new XmlDocument(); doc.LoadXml(sr.ReadToEnd()); sr.Close(); return doc.SelectSingleNode("//@targetNamespace").Value; } private static byte[] EncodeParsToSoap(Hashtable Pars , String XmlNs , String MethodName) { XmlDocument doc = new XmlDocument(); doc.LoadXml("<soap:Envelope xmlns:xsi=/"http://www./2001/XMLSchema-instance/" xmlns:xsd=/"http://www./2001/XMLSchema/" xmlns:soap=/"http://schemas./soap/envelope//"></soap:Envelope>"); AddDelaration(doc); XmlElement soapBody = doc.CreateElement("soap" , "Body" , "http://schemas./soap/envelope/"); XmlElement soapMethod = doc.CreateElement(MethodName); soapMethod.SetAttribute("xmlns" , XmlNs); foreach (string k in Pars.Keys) { XmlElement soapPar = doc.CreateElement(k); soapPar.InnerXml = ObjectToSoapXml(Pars[k]); soapMethod.AppendChild(soapPar); } soapBody.AppendChild(soapMethod); doc.DocumentElement.AppendChild(soapBody); return Encoding.UTF8.GetBytes(doc.OuterXml); } private static string ObjectToSoapXml(object o) { XmlSerializer mySerializer = new XmlSerializer(o.GetType()); MemoryStream ms=new MemoryStream(); mySerializer.Serialize(ms,o); XmlDocument doc=new XmlDocument(); doc.LoadXml(Encoding.UTF8.GetString(ms.ToArray())); if(doc.DocumentElement !=null) { return doc.DocumentElement.InnerXml ; } else { return o.ToString(); } } private static void SetWebRequest(HttpWebRequest request)
{ request.Credentials = CredentialCache.DefaultCredentials; request.Timeout = 10000; } private static void WriteRequestData(HttpWebRequest request , byte[] data) { request.ContentLength = data.Length; Stream writer = request.GetRequestStream(); writer.Write(data , 0 , data.Length); writer.Close(); } private static byte[] EncodePars(Hashtable Pars) { return Encoding.UTF8.GetBytes(ParsToString(Pars)); } private static String ParsToString(Hashtable Pars) { StringBuilder sb = new StringBuilder(); foreach (string k in Pars.Keys) { if (sb.Length > 0) { sb.Append("&"); } sb.Append(HttpUtility.UrlEncode(k) + "=" + HttpUtility.UrlEncode(Pars[k].ToString())); } return sb.ToString(); } private static XmlDocument ReadXmlResponse(WebResponse response) { StreamReader sr = new StreamReader(response.GetResponseStream() , Encoding.UTF8); String retXml = sr.ReadToEnd(); sr.Close(); XmlDocument doc = new XmlDocument(); doc.LoadXml(retXml); return doc; } private static void AddDelaration(XmlDocument doc) { XmlDeclaration decl = doc.CreateXmlDeclaration("1.0" , "utf-8" , null); doc.InsertBefore(decl , doc.DocumentElement); } }
这个类有三个公用的方法：QuerySoapWebService为通用的采用Soap方式调用WebService，QueryGetWebService采用GET方式调用，QueryPostWebService采用POST方式调用，后两个方法需要WebService服务器支持相应的调用方式。三个方法的参数和返回值相同：URL为Webservice的Url地址(以.asmx结尾的)；MethodName为要调用的方法名称；Pars为参数表，它的Key为参数名称，Value为要传递的参数的值,Value可为任意对象，前提是这个对象可以被xml序列化。注意方法名称、参数名称、参数个数必须完全匹配才能正确调用。第一次以Soap方式调用时，因为需要查询WSDL获取xmlns，因此需要时间相对长些，第二次调用不用再读WSDL，直接从缓存读取。这三个方法的返回值均为XmlDocument对象，这个返回的对象可以进行各种灵活的操作。最常用的一个SelectSingleNode方法，可以让你一步定位到Xml的任何节点，再读取它的文本或属性。也可以直接调用Save保存到磁盘。采用Soap方式调用时，根结点名称固定为root。 这个类主要是利用了WebRequest/WebResponse来完成各种网络查询操作。为了精简明了，这个类中没有添加错误处理，需要在调用的地方设置异常捕获。 下面是一个调用实例：
 protected void Page_Load(object sender , EventArgs e) { try { Hashtable pars = new Hashtable(); String Url = "http://www./Services/Weather.asmx"; pars["city"] = "上海"; pars["wdate"]="2008-3-19"; XmlDocument doc = WebSvcCaller.QuerySoapWebService(Url , "GetWeather" , pars); Response.Write(doc.OuterXml); } catch (Exception ex) { Response.Write(ex.Message); } } |
|
|
